Telephone signal system



(No Model.) 6 Sheets-Sheet 3.

W. A. STILWELLK: A. BARNEGK. TELEPHONE SIGNAL SYSTEM.

N0. 604,434 Patented May 24,1898.

(No Model.) 6 Sheets-Sheet 4.

W. A. STILWELL & A. BARNEOK.

TELEPHONE SIGNAL SYSTEM.

' N0.604,434. Patented May 24,1898.

6 Sheets-Sheet 5.

(No Model.) I

W. A. STILWELL & A. BARNEOK. TELEPHONE SIGNAL SYSTEM. Nd. 604,434.Patented May 24,1898.

(No Model.) e Sheets' Sheet 6.

W. A. STILWELL & A. BARNEGK.

TELEPHONE SIGNAL SYSTEM.

No. 604,434. Patented May Z4,189 8.4

THE mam; PETERS 00.. PNOTO-LITHO WASNXNOTON D c UNIT-E STATES PATENTOFFICE.

WALLAGE'A. STILWELL AND'ALEXANDER BARNEOK, OF-SALINA, KANSAS.

TELEPHONE SIGNAL SYSTEM.

SPECIFICATION forming part of Letters Patent N 0. 604,434, dated May24., 1898.

Application filed November 10, 1896. Serial No. 611,656. (No model.)

T at whom it may concern: 7 V

Be it known that we, WALLACE A. STIL- WELL and ALEXANDER BARNEOK,citizens of the United States, residing at Salina, in the county ofSaline and State of Kansas, have invented certain new and usefulImprovements in Telephone Signal Systems; and we do declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

Our invention relates to improvements in telephone signal systems inwhich a series of subscribers or sub stations are connected with acentral station, and the object is to provide a simple and reliablemeans whereby any one subscriber can connect his telephone with anyother subscriber at will.

To this end the invention comprises a central office in which is locatedaseries of switchboards, one for each distant orsubscribers station, apair of conductor-wires leading from each board to each of the otherswitchboards, one of these wires terminating in a spring-contact whichnormally contacts with one of a series of shoes which are connected by acommon conductor and also connected to a unison-post which is normallyin contact with a rotating contact-arm having a ground connectionthrough the corresponding telephone, and the other wire of each pairleads from a fixed contactp'ost located in the path of and adapted to beengaged by a spring-contact carried by said rotating contact-arm, aswill be hereinafter more fully described, and particularly pointed outin the claims.

In the accompanying drawings the same reference-numerals indicate thesame parts of the invention.

Figure 1 is a diagrammatic View of our improved signaling system,showing the same arranged for four substations or subscribers, theinstruments all being set at unison. Fig. 2 is a similar view in whichstation No. 2 is connected for ordinary communication with station No.4and station N0. 1 is connected for confidential communication withstation No. 3. Fig. 3 is afront elevation of the subscriberssignal-switch. Fig. 4 is a detail view of the rear face of theswitch-disk. Fig. 5is a top plan view of the signal-switch. Fig. 6 is aplan View of the transmitting-switch.

' same.

Fig. 7 is a transverse vertical section of the Fig. 8 is an endelevation, partly in section, of the signal-switch. Fig. 9 is a frontelevation of the signal-switch, taken on the line a a. of Fig. 8. Fig.10 is a detail perspective view of the rotating arm 27 and thecontiguous face of the disk 33, carrying the contact-points throughwhich communication isestablished between the stations. I

1 represents a base-plate, and 2 and 3 the integral vertical standards,in which is journaled a horizontal shaft 4. 5 represents a sleeveloosely mounted on said shaft, and about midway of its length it isformed with an integral depending arm 6, on the lower end of which issecured an armature 7, provided with the usual adjustable retractilespring 8, and 9'is" an electromagnet in communication with thebinding-posts 10 12. 13 represents a horizontal lever fixed on the outerend of said sleeve, its free end being adj ustably limited in movementby the adjusting-screws 14. 15 in the standard 16.

17 represents a pawl pivoted on the side of the lever 13 and held incontact with the teeth on the ratchet-wheel 18 bya spring 19. Thisratchet-wheel is adj ustably secured on the shaft 4 by a set-screw 20,and each impulse of the magnet moves the ratchet-wheel one tooth throughthe medium of the lever 13 and pawl 17.

20 is the usual retainingpawl, pivoted on the standard 2 and held incontact with the ratchet-wheel 18 by a spring 21, its office being toprevent any back motion.

22 represents a short horizontal arm fixed on the inner end of thesleeve 5, and to the outer end of said arm is pivoted the upper end ofaconnecting-rod 23, the lower end of which is pivoted to a pawl 24.,fulcrumed on a bracket 25, integral with the standard 3. The inner freeend of this pawl engages the teeth on the ratchet-wheel 26, fixed on theshaft 5, and the teeth on this ratchet-wheel incline in the reversedirection to those on the ratchet 18, the oflice of the ratchet wheel 26and pawl 24 being to prevent the shaft 5 from moving more than one stepahead at a time when the armature 7 is operated,

The inner end of the shaft 5 projects ing end is mounted a radial arm27, being adjustably secured in place by a set-screw 28,

and its outer end is provided with two contact-springs 29 30, the arm 27and shaft 5 being in electrical connection with the bindingpost 31 onthe base 1 through the contactspring 32, bearing against the end of theshaft 5, as shown in Fig. 8.

33 represents a fixed vertical disk of any suitable non-conductingmaterial, the face of which, contiguous to the arm 27, being, providedwith an annular series of contact-points, each member of the seriesconsisting of points-viz, a spring 34, a shoe 35, and a post 36, thespring and the post being located in the path of the contact-springs 29and 30, respectively, and in their normal position the spring 34 isalways in contact with the shoe 35. The number of the series ofcontactpoints on the disk 33 is the same as the number of teeth on theratchet-wheels, which also corresponds to the number of substations incommunication. There is also a single post 37, which is termed theunison-post, on which the arm 27 rests when the instrument is not inuse.

In .the sectional View shown in Fig. 8 it will be seen that each spring34 is' connected to a post or rod a, which extends through the disk 33,and its opposite end is provided with a conductor 79, which correspondsto the conductor 34 on the first instrument in Figs. 1 and 2. The posts36 also extend through the disk, and their opposite ends are eachprovided with a conductor 0, which corresponds to the conductor 35 onthe first instrument in Figs. 1 and 2.

The unison-post 37 is connected by a rod 37 with the com m on conductor54, so called because it is connected by the rods 35 with one of theshoes 35 on the face of the disk 33.

Referring to Figs. 6 and 7, which represent the transmitting-switch, 38is a non-conducting disk provided with an annular series ofcontact-points 39 in electrical connection with a common conductor 40,and 41 is a springlever mounted on a central post 42 and in electricalconnection with the conductor 43, the lever being adapted to swingaround on the contact-points 39 and open and close the circuit as manytimes as there are contact points on the disk 38, and when said lever 41is at its normal position its point of contact rests on the disk betweenthe last and the first contact-pointsay N o. 1thus leaving the circuitat its end of the conductors 40 and 43 open.

Referring to Fig. 1, the large numerals 1, 2, 3, and 4 indicate the foursubstations or subscribers telephones, and l 2 3 4 represent therespective signal-switches located in a central office. Each telephoneis connected with the arm 27 of its respective signal-switch by a singleconductor, as 44, 45, 46, and 47, respectively, and with-the earth by agroundwire 48, 49, 50, and 51. Each transmittingswitch 38 likewise has aground-wire 40 4O 40 40 respectively, and a line-wire 43, 43',

43 and 43 which is in communication with the magnet 9 of its respectivesignal-switch in the central office, the circuits of which are completedthrough a common conductor 52 through the common battery 53 to theground.

The series of shoes 35 on the face of the disk 33 on each instrument areconnected to conducting-rods 35, which extend through said disk andconnect to a common conductor 54,- fixed on the back of the disk 33.This common conductor 54 is simply a metallic ring, to whichthe rod 35from each shoe 35 is soldered. The unison-post 37 of each instrument islikewise connected to said common conductor 54 on the same instrument.

By referring to Figs. 1 and 2 it will be seen that the first post 36 onthe first instrument is connected by a conductor 35 with the first ofthe series of springs 34 on the second instrument, and the contiguousspring 34 on the first instrument is in electrical connec tion by aconductor 34 with the first post 36 contiguous to the first spring 34 onthe second instrument. The second post 36 on the first instrument isconnected by a conductor 57 with the first spring 34 on the thirdinstrument, and the contiguous spring 34 on the first instrument iselectrically connected by a conductor 56 with the first post 36contiguous to the first spring 34 on the third instru ment. The thirdpost 36 on the first instrument is connected by a conductor 58 with thefirst spring 34 on the fourth instrument, and the corresponding spring.34 on the first instrument is connected by a conductor 59 with the firstpost 36 on the fourth instrument. The second post 36 and its spring 34on the second instrument are similarly connected by the conductors 6061, respectively, with the second spring 34 and post 36 on the thirdinstrument, and the third post 36 and spring 34 on the second instrumentare connected by the conductors 55 55, respectively, with the secondspring 34 and post 36 on the fourth instrument. The third post 36 andspring 34 on the third instrument are connected by the conductors 62 and63, respectively, with the third spring 34 and post 36 on the fourthinstrument, and so on throughout the remainder of the series. Thus, forinstance, the connection between any two instruments, say one and two,is as follows: 34, 56, and 59 connect with each of the contacts 34 atone, and the wires 35 57, and 58 connect the post 36 with the post 36 attwo, three, and four, and the common conductor 54 (shown in dottedlines) connects all the shoes and post 37 at each instrument. Thisarrangement gives two independent conductors between each pair in theseries, and by referring to Fig. 2 it will be seen that No. 2 has movedhis transmitter-switch to the fourth post. This means that he has closedand opened his transmitter switch circuit four times and consequentlysent four impulses through his signal-switch magnet 9 four times andmoved l i l l 1 v i i i r 604,434 I V s the arm 27 to the fourthcontact-point, as shown, and in so doing the contact-spring 29 on saidarm rests on the spring 34 in contact with it and at the same timebreaking its contact with its shoe 35. The contact-spring 30 on the arm27 is also in connection with the post 36 immediately below said shoe.The condition of affairs now is that No. .2 has established a circuitover his wire 45, arm 27, and spring 30 with the post 36,'and thenceover the wire 55 to the second spring 34 on N 0.4 instrument and throughsaid spring to its shoe 35, thence through the common conductor 54 tothe unison-post 37 through the contact-spring 30 on the arm 27 to thewire 47 to No. 4s telephone, and thence through wire 51 to the ground,which places Nos. 2 and 4 in circuit for ordinary conversation, forwhile No. 2 is cut out from all the other instruments No. 4s telephoneis still connected to the common conductor 54 on his signalswitch, andconsequently if any other subscriber were to switch onto No. 4 he wouldthen be in the same position as No. 2 and in communication with Nos. 4and 2 as well.

By referring to Fig. 2 it will be seen that Nos. 2 and 4 are incommunication, as above indicated, for ordinary conversation, and in thesame figure we show how any two substantionsas Nos. 1 and 3, for example are connected for confidential or secret communication that is, No.1 moves his signal-transmitter, and consequently the arm 27 of hissignal-switch, three points, which connects the spring 29 on his arm 27.with the spring 34 and the conductor 56 to the post 36 on No. 3s switch.No. 3 then moves his transmitter to No. 1, which places the spring 29 onhis arm 27 in contact with the spring 34 on his own instrument and fromthat over the conductor 57 to the post 36 on No. ls instrument, and asthe unison-posts 37 on each instrument are the only means ofcommunication common to all the instruments it follows that when the arm27 of a particular subscribers instrument is off of its unison-post hecan only be communicated with by the subscriber on whose line he isswitched. Of course it will be understood that when any two instrumentsare connected, as above described, for confidential conversation thecurrent is split at the switch-arm 27 and follows both conductors. Asrepresented in the diagram in Fig. 2, it will be seen that No. ls arm 27is on the conductor 56 leading to No. 3s post 36 and No. 3s arm 27 is onthe conductor 57 leading to No. ls-post 36, and as both of the arms 27are off their respective union-posts 37 they are both out off fromcommunication with all the other instruments in the system.

Of course it will be understood that when a subscriber is throughtalking he carries his transmitter-switch around to the startingpoint,which brings the arm 27 of his instrument around to the unison-post,which places his instrument in position for communication with all theothers, and if two subscribers have arranged their instruments forsecret communication both of course must restore their respectiveinstruments to unison.

Having thus fully described our invention, what we claim as new, anddesire tosecure by Letters Patent, is-- 1. A telephone-exchange system,comprising a central office in which is located a series ofswitchboards, one for each distant or subscribers station, a pair ofconductor-wires leading fromeach board to each of the otherswitchboards, one of these wires terminating in a spring contact-point34 which normally contacts with one of a series of contact-shoes 35,which are connected by a common conductor 54, and also connected to aunison-post 37 which is normally in contact with a rotating contact-arm27 having a ground connection through the corresponding telephone, andthe other wire of each pair leading from a fixed contact-post 36 locatedin the path of and adapted to be engaged by a spring contactfinger 30carried by said rotating contact-arm 27, as and for the purpose setforth.-

2. A telephone-switchboard comprising two seriesof fixed contactsarranged in concentric circles, a common conductor normally connectedwith each contact of one of the series, a series of wires arranged inpairs, the ends of the wires of each pair terminating in a contact ineach series, a switch-arm movably secured relatively to the series ofcontacts and normally electrically connected purpose set forth.

3. A telephone signal system comprising an electrically-operated switchhaving a movable switch-arm carrying two contact-points as 29 and 30,and permanently connected through a telephone-station with the ground,of a series of individual conductors arranged in pairs, the contiguousends of each pair terminating in the path of said contact-points 29 and30, one end of one wire of each of which pairs is connected to aninsulated contact-post as 36, and the other wire to a contact-spring as34, normally in contact with a common conductor as 54, said commonconductor having a normal ground connection through the switch-arm, asand for the purpose set forth. In testimony whereof we hereunto affixour signatures in presence of two witnesses.

WALLACE A. STILWELL. ALEXANDER BARNECK. WVitnesses:

F. A. BARNETT, T. N. BARNETT.

